Heat-assisted magnetic recording head with near-field light generating element

ABSTRACT

A near-field light generating element has an outer surface. The outer surface includes a bottom surface, first and second inclined surfaces, an edge part that connects the first and second inclined surfaces to each other, and a front end face located in a medium facing surface. The front end face includes a first side that lies at an end of the first inclined surface, a second side that lies at an end of the second inclined surface, and a tip that is formed by contact of the first and second sides with each other and forms a near-field light generating part. Each of the first side and the second side has a lower part and an upper part that are continuous with each other. An angle formed between the upper part of the first side and the upper part of the second side is smaller than that formed between the lower part of the first side and the lower part of the second side.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a near-field light generating elementfor use in heat-assisted magnetic recording where a recording medium isirradiated with near-field light to lower the coercivity of therecording medium for data writing, a method of manufacturing the same,and a heat-assisted magnetic recording head that includes the near-fieldlight generating element.

2. Description of the Related Art

Recently, magnetic recording devices such as magnetic disk drives havebeen improved in recording density, and thin-film magnetic heads andrecording media of improved performance have been demanded accordingly.Among the thin-film magnetic heads, a composite thin-film magnetic headhas been used widely. The composite thin-film magnetic head has such astructure that a read head including a magnetoresistive element(hereinafter, also referred to as MR element) for reading and a writehead including an induction-type electromagnetic transducer for writingare stacked on a substrate. In a magnetic disk drive, the thin-filmmagnetic head is mounted on a slider that flies slightly above thesurface of the magnetic recording medium.

To increase the recording density of a magnetic recording device, it iseffective to make the magnetic fine particles of the recording mediumsmaller. Making the magnetic fine particles smaller, however, causes theproblem that the magnetic fine particles drop in the thermal stabilityof magnetization. To solve this problem, it is effective to increase theanisotropic energy of the magnetic fine particles. However, increasingthe anisotropic energy of the magnetic fine particles leads to anincrease in coercivity of the recording medium, and this makes itdifficult to perform data writing with existing magnetic heads.

To solve the foregoing problems, there has been proposed a techniqueso-called heat-assisted magnetic recording. This technique uses arecording medium having high coercivity. When writing data, a magneticfield and heat are simultaneously applied to the area of the recordingmedium where to write data, so that the area rises in temperature anddrops in coercivity for data writing. The area where data is writtensubsequently falls in temperature and rises in coercivity to increasethe thermal stability of magnetization. Hereinafter, a magnetic head foruse in heat-assisted magnetic recording will be referred to as aheat-assisted magnetic recording head.

In heat-assisted magnetic recording, near-field light is typically usedas a means for applying heat to the recording medium. A known method forgenerating near-field light is to apply laser light to a plasmonantenna, which is a small piece of metal, as described in U.S. PatentApplication Publication No. 2008/0055762 A1, for example. The laserlight applied to the plasmon antenna excites surface plasmons on theplasmon antenna, and near-field light is generated based on the surfaceplasmons. The near-field light generated by the plasmon antenna existsonly within an area smaller than the diffraction limit of light.Irradiating the recording medium with the near-field light makes itpossible to heat only a small area of the recording medium.

A possible configuration of the heat-assisted magnetic recording head issuch that, in a medium facing surface that faces the recording medium,an end face of a magnetic pole that produces a write magnetic field islocated on the trailing side relative to a front end face of anear-field light generating element which is a piece of metal thatgenerates near-field light. The trailing side relative to a referenceposition refers to the side closer to the air outflow end of the sliderrelative to the reference position. The trailing side typically falls onthe side farther from the top surface of the substrate relative to thereference position. When the above-described configuration is employed,the front end face of the near-field light generating element preferablyhas a pointed top end so that a near-field light generating part isformed near the top end of the front end face.

In order to increase the recording density of the magnetic recordingdevice, it is preferred that the near-field light have a smaller spotdiameter. When the foregoing configuration is employed, it is effectiveto form the top end of the front end face of the near-field lightgenerating element into a more sharply pointed shape so as to producenear-field light having a small spot diameter and sufficient intensity.

As a method for forming the near-field light generating element havingthe front end face with a pointed top end, a metal film to make thenear-field light generating element may be etched by using an etchingmask of photoresist. The formation of the near-field light generatingelement by such a method, however, has the problem that the top end ofthe front end face will become rounded, and it is thus difficult to forma near-field light generating element having a front end face with asharply pointed top end.

OBJECT AND SUMMARY OF THE INVENTION

It is an object of the present invention to provide a near-field lightgenerating element having a front end face with a sharply pointed topend and a method of manufacturing the same, and a heat-assisted magneticrecording head including such a near-field light generating element.

A near-field light generating element of the present invention is foruse in a heat-assisted magnetic recording head. The heat-assistedmagnetic recording head includes: a medium facing surface that faces arecording medium; a magnetic pole; a waveguide that propagates light;the near-field light generating element; and a substrate having a topsurface. The magnetic pole has an end face located in the medium facingsurface and produces a write magnetic field for writing data on therecording medium. The near-field light generating element has anear-field light generating part located in the medium facing surface. Asurface plasmon is excited based on the light propagated through thewaveguide. The surface plasmon is propagated to the near-field lightgenerating part. The near-field light generating part generatesnear-field light based on the surface plasmon. The near-field lightgenerating element, the magnetic pole, and the waveguide are disposedabove the top surface of the substrate.

The near-field light generating element of the present invention has anouter surface. The outer surface includes: a bottom surface that lies atan end closer to the top surface of the substrate; first and secondinclined surfaces that are each connected to the bottom surface, thefirst and second inclined surfaces decreasing in distance from eachother with increasing distance from the bottom surface; an edge partthat connects the first and second inclined surfaces to each other; anda front end face that is located in the medium facing surface andconnects the bottom surface and the first and second inclined surfacesto each other. The front end face has: a first side that lies at an endof the first inclined surface; a second side that lies at an end of thesecond inclined surface; a third side that lies at an end of the bottomsurface; and a tip that is formed by contact of the first and secondsides with each other and forms the near-field light generating part.Each of the first side and the second side includes a lower part and anupper part that are continuous with each other. An angle formed betweenthe upper part of the first side and the upper part of the second sideis smaller than that formed between the lower part of the first side andthe lower part of the second side.

In the near-field light generating element of the present invention,each of the first inclined surface and the second inclined surface mayinclude a lower part and an upper part that are continuous with eachother. In such a case, an angle formed between the upper part of thefirst inclined surface and the upper part of the second inclined surfacemay be smaller than that formed between the lower part of the firstinclined and the lower part of the second inclined surface. The lowerpart of the first side may lie at an end of the lower part of the firstinclined surface. The upper part of the first side may lie at an end ofthe upper part of the first inclined surface. The lower part of thesecond side may lie at an end of the lower part of the second inclinedsurface. The upper part of the second side may lie at an end of theupper part of the second inclined surface.

Each of first and second methods of manufacturing a near-field lightgenerating element of the present invention is a method of manufacturinga near-field light generating element where each of the first inclinedsurface and the second inclined surface includes the lower part and theupper part that are continuous with each other.

The first method of manufacturing the near-field light generatingelement of the present invention includes: a step of forming a metallayer that is to be etched later to become the near-field lightgenerating element; a first etching step of etching the metal layer sothat the metal layer is provided with the first inclined surface; and asecond etching step of etching the metal layer so that the metal layeris provided with the second inclined surface and the edge part andthereby becomes the near-field light generating element.

The second method of manufacturing the near-field light generatingelement of the present invention includes: a step of forming a metallayer that is to be etched later to become the near-field lightgenerating element; a step of forming a polishing stopper layer on themetal layer, the polishing stopper layer being intended for use in apolishing step to be performed later; a first etching step of etchingthe polishing stopper layer and the metal layer so that the metal layeris provided with the first inclined surface; a step of forming a coatinglayer to cover the polishing stopper layer and the metal layer providedwith the first inclined surface, the coating layer being made of anon-metallic inorganic material that has an etching rate lower than thatof the metal layer in a second etching step to be performed later; thepolishing step of polishing the coating layer until the polishingstopper layer is exposed; and the second etching step of etching thepolishing stopper layer and the metal layer by using the coating layerpolished in the polishing step as an etching mask so that the metallayer is provided with the second inclined surface and the edge part andthereby becomes the near-field light generating element.

In the first and second methods of manufacturing the near-field lightgenerating element of the present invention, the first etching stepincludes: a step of providing the metal layer with a first initialinclined surface that is to become the first inclined surface later; anda step of etching the first initial inclined surface so that the firstinitial inclined surface is provided with the lower part and the upperpart of the first inclined surface and thereby becomes the firstinclined surface. The second etching step includes: a step of providingthe metal layer with a second initial inclined surface that is to becomethe second inclined surface later; and a step of etching the secondinitial inclined surface so that the second initial inclined surface isprovided with the lower part and the upper part of the second inclinedsurface and thereby becomes the second inclined surface.

In the second method of manufacturing the near-field light generatingelement of the present invention, the coating layer may be made of oneselected from the group consisting of Al₂O₃, SiO₂, Ta₂O₅, SiC, and TiN.

A heat-assisted magnetic recording head of the present inventionincludes: a medium facing surface that faces a recording medium; amagnetic pole; a waveguide that propagates light; a near-field lightgenerating element; and a substrate having a top surface. The magneticpole has an end face located in the medium facing surface and produces awrite magnetic field for writing data on the recording medium. Thenear-field light generating element has a near-field light generatingpart located in the medium facing surface. A surface plasmon is excitedbased on the light propagated through the waveguide. The surface plasmonis propagated to the near-field light generating part. The near-fieldlight generating part generates near-field light based on the surfaceplasmon. The near-field light generating element, the magnetic pole, andthe waveguide are disposed above the top surface of the substrate.

In the heat-assisted magnetic recording head of the present invention,the near-field light generating element has an outer surface. The outersurface includes: a bottom surface that lies at an end closer to the topsurface of the substrate; first and second inclined surfaces that areeach connected to the bottom surface, the first and second inclinedsurfaces decreasing in distance from each other with increasing distancefrom the bottom surface; an edge part that connects the first and secondinclined surfaces to each other; and a front end face that is located inthe medium facing surface and connects the bottom surface and the firstand second inclined surfaces to each other. The front end face has: afirst side that lies at an end of the first inclined surface; a secondside that lies at an end of the second inclined surface; a third sidethat lies at an end of the bottom surface; and a tip that is formed bycontact of the first and second sides with each other and forms thenear-field light generating part. Each of the first side and the secondside includes a lower part and an upper part that are continuous witheach other. An angle formed between the upper part of the first side andthe upper part of the second side is smaller than that formed betweenthe lower part of the first side and the lower part of the second side.

In the heat-assisted magnetic recording head of the present invention,each of the first inclined surface and the second inclined surface mayinclude a lower part and an upper part that are continuous with eachother. In such a case, an angle formed between the upper part of thefirst inclined surface and the upper part of the second inclined surfacemay be smaller than that formed between the lower part of the firstinclined and the lower part of the second inclined surface. The lowerpart of the first side may lie at an end of the lower part of the firstinclined surface. The upper part of the first side may lie at an end ofthe upper part of the first inclined surface. The lower part of thesecond side may lie at an end of the lower part of the second inclinedsurface. The upper part of the second side may lie at an end of theupper part of the second inclined surface.

In the heat-assisted magnetic recording head of the present invention,the magnetic pole may have a bottom end that is opposed to the edge partof the near-field light generating element.

In the heat-assisted magnetic recording head of the present invention,the waveguide may have a bottom surface that is opposed to the edge partof the near-field light generating element.

In the near-field light generating element or the heat-assisted magneticrecording head of the present invention, the outer surface of thenear-field light generating element includes the bottom surface, thefirst and second inclined surfaces, the edge part that connects thefirst and second inclined surfaces to each other, and the front end facelocated in the medium facing surface. The front end face includes thefirst side lying at an end of the first inclines surface, the secondside lying at an end of the second inclined surface, the third sidelying at an end of the bottom surface, and the tip that is formed bycontact of the first and second sides with each other and forms thenear-field light generating part. Each of the first side and the secondside includes the lower part and the upper part that are continuous witheach other. The angle formed between the upper part of the first sideand the upper part of the second side is smaller than that formedbetween the lower part of the first side and the lower part of thesecond inclined side. Consequently, according to the present invention,it is possible to form the top end (tip) of the front end face of thenear-field light generating element into a sharply pointed shape.

Each of the first and second methods of manufacturing the near-fieldlight generating element of the present invention includes the firstetching step of etching a metal layer so that the metal layer isprovided with the first inclined surface, and the second etching step ofetching the metal layer so that the metal layer is provided with thesecond inclined surface and the edge part and thereby becomes thenear-field light generating element. The first etching step includes:the step of providing the metal layer with a first initial inclinedsurface that is to become the first inclined surface later; and the stepof etching the first initial inclined surface so that the first initialinclined surface is provided with the lower part and the upper part ofthe first inclined surface and thereby becomes the first inclinedsurface. The second etching step includes: the step of providing themetal layer with a second initial inclined surface that is to become thesecond inclined surface later; and the step of etching the secondinitial inclined surface so that the second initial inclined surface isprovided with the lower part and the upper part of the second inclinedsurface and thereby becomes the second inclined surface. Consequently,according to the present invention, it is possible to form a near-fieldlight generating element having a front end face with a sharply pointedtop end (tip).

Other and further objects, features and advantages of the presentinvention will appear more fully from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing a near-field light generatingelement according to a first embodiment of the invention.

FIG. 2 is a front view showing a front end face of the near-field lightgenerating element of FIG. 1.

FIG. 3 is a perspective view showing the main part of a heat-assistedmagnetic recording head according to the first embodiment of theinvention.

FIG. 4 is a cross-sectional view showing the configuration of theheat-assisted magnetic recording head according to the first embodimentof the invention.

FIG. 5 is a front view showing the medium facing surface of theheat-assisted magnetic recording head according to the first embodimentof the invention.

FIG. 6 is a plan view showing a first layer of a coil of theheat-assisted magnetic recording head according to the first embodimentof the invention.

FIG. 7 is a plan view showing a second layer of the coil of theheat-assisted magnetic recording head according to the first embodimentof the invention.

FIG. 8 is a cross-sectional view showing a step of a method ofmanufacturing the heat-assisted magnetic recording head according to thefirst embodiment of the invention.

FIG. 9 is a cross-sectional view showing a step that follows the step ofFIG. 8.

FIG. 10 is a cross-sectional view showing a step that follows the stepof FIG. 9.

FIG. 11 is a cross-sectional view showing a step that follows the stepof FIG. 10.

FIG. 12 is a cross-sectional view showing a step that follows the stepof FIG. 11.

FIG. 13 is a cross-sectional view showing a step that follows the stepof FIG. 12.

FIG. 14 is a cross-sectional view showing a step that follows the stepof FIG. 13.

FIG. 15 is a cross-sectional view showing a step that follows the stepof FIG. 14.

FIG. 16 is a cross-sectional view showing a step that follows the stepof FIG. 15.

FIG. 17 is a cross-sectional view showing a step that follows the stepof FIG. 16.

FIG. 18 is a cross-sectional view showing a step that follows the stepof FIG. 17.

FIG. 19 is a cross-sectional view showing a step that follows the stepof FIG. 18.

FIG. 20 is a cross-sectional view showing a step that follows the stepof FIG. 19.

FIG. 21 is a cross-sectional view showing a step that follows the stepof FIG. 20.

FIG. 22 is a cross-sectional view showing a step of a method ofmanufacturing a heat-assisted magnetic recording head according to asecond embodiment of the invention.

FIG. 23 is a cross-sectional view showing a step that follows the stepof FIG. 22.

FIG. 24 is a cross-sectional view showing a step that follows the stepof FIG. 23.

FIG. 25 is a cross-sectional view showing a step that follows the stepof FIG. 24.

FIG. 26 is a cross-sectional view showing a step that follows the stepof FIG. 25.

FIG. 27 is a cross-sectional view showing a step that follows the stepof FIG. 26.

FIG. 28 is a cross-sectional view showing a step that follows the stepof FIG. 27.

FIG. 29 is a cross-sectional view showing a step that follows the stepof FIG. 28.

FIG. 30 is a cross-sectional view showing a step that follows the stepof FIG. 29.

FIG. 31 is a cross-sectional view showing a step that follows the stepof FIG. 30.

FIG. 32 is a cross-sectional view showing a step that follows the stepof FIG. 31.

FIG. 33 is a cross-sectional view showing a step that follows the stepof FIG. 32.

FIG. 34 is a cross-sectional view showing a step that follows the stepof FIG. 33.

FIG. 35 is a cross-sectional view showing a step that follows the stepof FIG. 34.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment

Preferred embodiments of the present invention will now be described indetail with reference to the drawings. First, reference is made to FIG.1 to FIG. 7 to describe the configuration of a heat-assisted magneticrecording head according to a first embodiment of the invention. FIG. 1is a perspective view showing a near-field light generating elementaccording to the present embodiment. FIG. 2 is a front view showing afront end face of the near-field light generating element of FIG. 1.FIG. 3 is a perspective view showing the main part of the heat-assistedmagnetic recording head. FIG. 4 is a cross-sectional view showing theconfiguration of the heat-assisted magnetic recording head. FIG. 5 is afront view showing the medium facing surface of the heat-assistedmagnetic recording head. FIG. 6 is a plan view showing a first layer ofa coil of the heat-assisted magnetic recording head. FIG. 7 is a planview showing a second layer of the coil of the heat-assisted magneticrecording head.

The heat-assisted magnetic recording head according to the presentembodiment is for use in perpendicular magnetic recording, and is in theform of a slider that flies over the surface of a recording medium thatis driven to rotate. When the recording medium rotates, an airflowpassing between the recording medium and the slider causes a lift to beexerted on the slider. The slider is configured to fly over the surfaceof the recording medium by means of the lift.

As shown in FIG. 4, the heat-assisted magnetic recording head has amedium facing surface 40 that faces the recording medium. Here, Xdirection, Y direction, and Z direction will be defined as follows. TheX direction is the direction across the tracks of the recording medium,i.e., the track width direction. The Y direction is a directionperpendicular to the medium facing surface 40. The Z direction is thedirection of travel of the recording medium as viewed from the slider.The X, Y, and Z directions are orthogonal to one another.

As shown in FIG. 4 and FIG. 5, the heat-assisted magnetic recording headincludes: a substrate 1 made of a ceramic material such as aluminumoxide-titanium carbide (Al₂O₃—TiC) and having a top surface 1 a; aninsulating layer 2 made of an insulating material and disposed on thetop surface 1 a of the substrate 1; and a bottom shield layer 3 made ofa magnetic material and disposed on the insulating layer 2. Theinsulating layer 2 is made of alumina (Al₂O₃), for example.

The heat-assisted magnetic recording head further includes: a bottomshield gap film 4 which is an insulating film disposed on the topsurface of the bottom shield layer 3; a magnetoresistive (MR) element 5as a read element disposed on the bottom shield gap film 4; two leads(not shown) connected to the MR element 5; a top shield gap film 6 whichis an insulating film disposed on the MR element 5; and a top shieldlayer 7 made of a magnetic material and disposed on the top shield gapfilm 6.

An end of the MR element 5 is located in the medium facing surface 40that faces the recording medium. The MR element 5 may be an element madeof a magneto-sensitive film that exhibits a magnetoresistive effect,such as an anisotropic magnetoresistive (AMR) element, a giantmagnetoresistive (GMR) element, or a tunneling magnetoresistive (TMR)element. The GMR element may be of either the current-in-plane (CIP)type in which a current used for detecting magnetic signals is fed in adirection nearly parallel to the plane of layers constituting the GMRelement or the current-perpendicular-to-plane (CPP) type in which thecurrent used for detecting magnetic signals is fed in a direction nearlyperpendicular to the plane of layers constituting the GMR element. Ifthe MR element 5 is a TMR element or a CPP-type GMR element, the bottomshield layer 3 and the top shield layer 7 may also function as the twoleads, with the top surface of the bottom shield layer 3 in contact withthe bottom surface of the MR element 5 and the bottom surface of the topshield layer 7 in contact with the top surface of the MR element 5. Theparts from the bottom shield layer 3 to the top shield layer 7constitute a read head.

The heat-assisted magnetic recording head further includes: anonmagnetic layer 8 made of a nonmagnetic material and disposed on thetop surface of the top shield layer 7; and a return magnetic pole layer10 made of a magnetic material and disposed on the nonmagnetic layer 8.The nonmagnetic layer 8 is made of alumina, for example.

The heat-assisted magnetic recording head further includes: a couplinglayer 11 made of a magnetic material and disposed on a part of the topsurface of the return magnetic pole layer 10 away from the medium facingsurface 40; and an insulating layer 12 disposed around the couplinglayer 11 on the top surface of the return magnetic pole layer 10. Theinsulating layer 12 is made of alumina, for example.

The heat-assisted magnetic recording head further includes: a couplinglayer 13 made of a magnetic material and disposed on the coupling layer11; a heat sink layer 14 disposed on a part of the top surface of theinsulating layer 12; and an insulating layer 15 disposed around thecoupling layer 13 and the heat sink layer 14 on the top surface of theinsulating layer 12. An end face of the heat sink layer 14 closer to themedium facing surface 40 is located at a distance from the medium facingsurface 40. A part of the insulating layer 15 is interposed between theend face of the heat sink layer 14 and the medium facing surface 40. Theheat sink layer 14 is made of a material having a high thermalconductivity, such as SiC. The insulating layer 15 is made of alumina,for example. The coupling layer 13, the heat sink layer 14, and theinsulating layer 15 are flattened at the top.

The heat-assisted magnetic recording head further includes: a near-fieldlight generating element 16 disposed on top of the heat sink layer 14and the insulating layer 15 in the vicinity of the medium facing surface40; a coupling layer 17 made of a magnetic material and disposed on thecoupling layer 13; and a surrounding layer 18 disposed on top of theheat sink layer 14 and the insulating layer 15 and surrounding thenear-field light generating element 16 and the coupling layer 17. Thesurrounding layer 18 may thinly cover the near-field light generatingelement 16. The near-field light generating element 16 is made of ametal. Specifically, the near-field light generating element 16 is madeof one of Au, Ag, Al, Cu, Pd, Pt, Rh and Ir, or of an alloy composed oftwo or more of these elements. At least part of the surrounding layer 18is made of a non-metallic inorganic material. The coupling layer 17 andthe surrounding layer 18 are flattened at the top.

The heat-assisted magnetic recording head further includes: a clad layer19 disposed over the top surfaces of the coupling layer 17 and thesurrounding layer 18; and a waveguide 20 and a magnetic pole 20 that aredisposed on the clad layer 19. The waveguide 20 is made of a dielectricmaterial that transmits laser light to be used for generating near-fieldlight. The laser light emitted from a not-shown laser diode enters thewaveguide 20 and is propagated through the waveguide 20. The clad layer19 is made of a dielectric material that has a refractive index lowerthan that of the waveguide 20. For example, the waveguide 20 can be madeof Ta₂O₅ which has a refractive index of approximately 2.1, and the cladlayer 19 can be made of alumina which has a refractive index ofapproximately 1.8.

The waveguide 20 includes a first layer 20A lying on the clad layer 19and a second layer 20B lying on the first layer 20A. The magnetic pole22 includes a first layer 22A lying on the clad layer 19, a second layer22B lying on the first layer 22A, and a third layer 22C lying on thesecond layer 22B.

The heat-assisted magnetic recording head further includes clad layers21 and 23. The clad layer 21 is disposed around the first layer 20A ofthe waveguide 20 and the first layer 22A of the magnetic pole 22 on theclad layer 19. The clad layer 23 is disposed around the second layer 20Bof the waveguide 20 and the second layer 22B of the magnetic pole 22 onthe clad layer 21. A part of the clad layer 23 covers the top surface ofthe second layer 20B. The clad layers 21 and 23 are each made of adielectric material that has a refractive index lower than that of thewaveguide 20. If the waveguide 20 is made of Ta₂O₅, the clad layers 21and 23 can be made of alumina, for example.

The heat-assisted magnetic recording head further includes: a couplinglayer 24 made of a magnetic material and disposed on a part of the cladlayer 23 above the coupling layer 17; and an insulating layer 25disposed around the third layer 22C of the magnetic pole 22 and thecoupling layer 24 on the clad layer 23. The insulating layer 25 is madeof alumina, for example. The coupling layer 24 is magnetically coupledto the coupling layer 17 via two coupling portions to be describedlater.

The heat-assisted magnetic recording head further includes: a couplinglayer 26 made of a magnetic material and disposed on the third layer 22Cof the magnetic pole 22; and a coupling layer 27 made of a magneticmaterial and disposed on the coupling layer 24.

The heat-assisted magnetic recording head further includes: aninsulating layer 28 disposed on the insulating layer 25; a plurality offirst coil elements 30A disposed on the insulating layer 28; and aninsulating layer 31 disposed around the coupling layers 26 and 27 andthe first coil elements 30A. FIG. 6 shows the first coil elements 30A.The first coil elements 30A are arranged to align in the Y direction.Each first coil element 30A has a main part that extends in the trackwidth direction (the X direction). Each first coil element 30A is madeof a conductive material such as copper. The insulating layers 28 and 31are made of alumina, for example.

The heat-assisted magnetic recording head further includes: aninsulating layer 32 disposed to cover the first coil elements 30A; and ayoke layer 33 made of a magnetic material and disposed over the couplinglayers 26 and 27 and the insulating layer 32. The yoke layer 33magnetically couples the coupling layer 26 to the coupling layer 27. Theinsulating layer 32 is made of alumina, for example.

The heat-assisted magnetic recording head further includes: aninsulating layer 34 disposed to cover the yoke layer 33; a plurality ofsecond coil elements 30B disposed on the insulating layer 34; a leadlayer 30C disposed on the insulating layer 34; and a protection layer 35disposed to cover the second coil elements 30B and the lead layer 30C.The insulating layer 34 and the protection layer 35 are made of alumina,for example.

FIG. 7 shows the second coil elements 30B and the lead layer 30C. Thesecond coil elements 30B are arranged to align in the Y direction. Eachsecond coil element 30B has a main part that extends in the track widthdirection (the X direction). Each second coil element 30B and the leadlayer 30C are made of a conductive material such as copper.

As shown in FIG. 6 and FIG. 7, the heat-assisted magnetic recording headfurther includes a plurality of connecting portions 36 and a connectingportion 37. The plurality of connecting portions 36 connect theplurality of first coil elements 30A to the plurality of second coilelements 30B so as to form a coil 30 wound around the yoke layer 33helically. The connecting portion 37 connects one of the first coilelements 30A to the lead layer 30C. The connecting portions 36 and theconnecting portion 37 are provided to penetrate through the insulatinglayer 34. The connecting portions 36 and the connecting portion 37 areeach made of a conductive material such as copper.

FIG. 6 further shows two coupling portions 29A and 29B that couple thecoupling layer 24 to the coupling layer 17. The coupling portions 29Aand 29B are provided to penetrate through the clad layers 19, 21, and23. The coupling portions 29A and 29B are disposed on opposite sides ofthe waveguide 20 in the track width direction (the X direction), eachbeing spaced from the waveguide 20. Although not shown, each of thecoupling portions 29A and 29B includes a first layer lying on thecoupling layer 17 and a second layer lying on the first layer.

The parts from the return magnetic pole layer 10 to the second coilelements 30B constitute a write head. The coil 30, which is composed ofthe first coil elements 30A, the second coil elements 30B and theconnecting portions 36, produces a magnetic field corresponding to datato be written on the recording medium. The return magnetic pole layer10, the coupling layers 11, 13 and 17, the coupling portions 29A and29B, the coupling layers 24 and 27, the yoke layer 33, the couplinglayer 26, and the magnetic pole 22 form a magnetic path for passing amagnetic flux corresponding to the magnetic field produced by the coil30. The magnetic pole 22 allows the magnetic flux corresponding to themagnetic field produced by the coil 30 to pass, and produces a writemagnetic field for writing data on the recording medium by means of aperpendicular magnetic recording system.

As has been described, the heat-assisted magnetic recording headaccording to the present embodiment includes the medium facing surface40 that faces the recording medium, the read head, and the write head.The read head and the write head are stacked on the substrate 1.Relative to the read head, the write head is located on the front side(trailing side) in the direction of travel of the recording medium (theZ direction).

The read head includes: the MR element 5 as the read element; the bottomshield layer 3 and the top shield layer 7 for shielding the MR element5, the bottom shield layer 3 and the top shield layer 7 having theirrespective portions that are located near the medium facing surface 40and are opposed to each other with the MR element 5 therebetween; thebottom shield gap film 4 disposed between the MR element 5 and thebottom shield layer 3; and the top shield gap film 6 disposed betweenthe MR element 5 and the top shield layer 7.

The write head includes the coil 30, the magnetic pole 22, the waveguide20, and the near-field light generating element 16. The coil 30 producesa magnetic field corresponding to data to be written on the recordingmedium. The magnetic pole 22 allows the magnetic flux corresponding tothe magnetic field produced by the coil 30 to pass, and produces a writemagnetic field for writing data on the recording medium by means of theperpendicular magnetic recording system. The waveguide 20 propagates thelaser light emitted from the not-shown laser diode.

A description will now be given of the near-field light generatingelement 16 with reference to FIG. 1 and FIG. 2. As shown in FIG. 1, thenear-field light generating element 16 has a near-field light generatingpart 16 g located in the medium facing surface 40. The near-field lightgenerating element 16 is generally triangular-prism-shaped, having anouter surface as described below. The outer surface of the near-fieldlight generating element 16 includes: a bottom surface 16 a; first andsecond inclined surfaces 16 b and 16 c that are each connected to thebottom surface 16 a, the first and second inclined surfaces 16 b and 16c decreasing in distance from each other with increasing distance fromthe bottom surface 16 a; and an edge part 16 d that connects the firstand second inclined surfaces 16 b and 16 c to each other. The bottomsurface 16 a has two sides 16 a 1 and 16 a 2 that are each parallel tothe direction perpendicular to the medium facing surface 40 (the Ydirection). The bottom end of the first inclined surface 16 b isconnected to the side 16 a 1, and the bottom end of the second inclinedsurface 16 c is connected to the side 16 a 2. The top end of the firstinclined surface 16 b and the top end of the second inclined surface 16c are connected to each other at the edge part 16 d.

The first inclined surface 16 b includes a lower part 16 b 1 and anupper part 16 b 2 that are continuous with each other. The secondinclined surface 16 c includes a lower part 16 c 1 and an upper part 16c 2 that are continuous with each other. The lower part 16 b 1, theupper part 16 b 2, the lower part 16 c 1, and the upper part 16 c 2 areeach planar or almost planar in shape. The bottom end of the lower part16 b 1 of the first inclined surface 16 b is connected to the side 16 a1. The bottom end of the lower part 16 c 1 of the second inclinedsurface 16 c is connected to the side 16 a 2. The top end of the upperpart 16 b 2 of the first inclined surface 16 b and the top end of theupper part 16 c 2 of the second inclined surface 16 c are connected toeach other at the edge part 16 d.

Here, the angle formed between the lower part 16 b 1 of the firstinclined surface 16 b and the lower part 16 c 1 of the second inclinedsurface 16 c will be designated by the symbol θ1. The angle formedbetween the upper part 16 b 2 of the first inclined surface 16 b and theupper part 16 c 2 of the second inclined surface 16 c will be designatedby the symbol θ2. The angle θ2 is smaller than the angle θ1. It shouldbe appreciated that the angle formed between the lower part 16 b 1 ofthe first inclined surface 16 b and the lower part 16 c 1 of the secondinclined surface 16 c refers to the angle that is formed between avirtual plane including the approximate plane of the lower part 16 b 1and a virtual plane including the approximate plane of the lower part 16c 1.

The outer surface of the near-field light generating element 16 furtherincludes a frond end face 16 e located in the medium facing surface 40,and a rear end face 16 f opposite to the front end face 16 e. The frontend face 16 e and the rear end face 16 f each connect the bottom surface16 a and the first and second inclined surfaces 16 b and 16 c to eachother.

The front end face 16 e has: a first side 16 e 1 that lies at an end ofthe first inclined surface 16 b; a second side 16 e 2 that lies at anend of the second inclined surface 16 c; a third side 16 e 3 that liesat an end of the bottom surface 16 a; and a tip 16 e 4 that is formed bycontact of the first side 16 e 1 and the second side 16 e 2 with eachother and forms the near-field light generating part 16 g. Thenear-field light generating part 16 g refers to the tip 16 e 4 and itsvicinity in the front end face 16 e.

The first side 16 e 1 includes a lower part 16 e 11 and an upper part 16e 12 that are continuous with each other. The second side 16 e 2includes a lower part 16 e 21 and an upper part 16 e 22 that arecontinuous with each other. The lower part 16 e 11 of the first side 16e 1 lies at an end of the lower part 16 b 1 of the first inclinedsurface 16 b. The upper part 16 e 12 of the first side 16 e 1 lies at anend of the upper part 16 b 2 of the first inclined surface 16 b. Thelower part 16 e 21 of the second side 16 e 2 lies at an end of the lowerpart 16 c 1 of the second inclined surface 16 c. The upper part 16 e 22of the second side 16 e 2 lies at an end of the upper part 16 c 2 of thesecond inclined surface 16 c. The lower part 16 e 11, the upper part 16e 12, the lower part 16 e 21, and the upper part 16 e 22 are eachstraight-line-shaped or almost straight-line-shaped. In FIG. 2, thesymbol 16 e 13 designates the point of connection between the lower part16 e 11 and the upper part 16 e 12, and the symbol 16 e 23 designatesthe point of connection between the lower part 16 e 21 and the upperpart 16 e 22.

The angle formed between the lower part 16 e 11 of the first side 16 e 1and the lower part 16 e 21 of the second side 16 e 2 is equal to theangle θ1 formed between the lower part 16 b 1 of the first inclinedsurface 16 b and the lower part 16 c 1 of the second inclined surface 16c. The angle formed between the upper part 16 e 12 of the first side 16e 1 and the upper part 16 e 22 of the second side 16 e 2 is equal to theangle θ2 formed between the upper part 16 b 2 of the first inclinedsurface 16 b and the upper part 16 c 2 of the second inclined surface 16c. Therefore, the angle θ2 formed between the upper part 16 e 12 of thefirst side 16 e 1 and the upper part 16 e 22 of the second side 16 e 2is smaller than the angle θ1 formed between the lower part 16 e 11 ofthe first side 16 e 1 and the lower part 16 e 21 of the second side 16 e2. It should be appreciated that the angle formed between the lower part16 e 11 of the first side 16 e 1 and the lower part 16 e 21 of thesecond side 16 e 2 refers to the angle that is formed between anextension of the approximate line of the lower part 16 e 11 and anextension of the approximate line of the lower part 16 e 21.

The angle θ1 preferably falls within the range of 60° to 120°. The angleθ2 preferably falls within the range of 30° to 60°.

Here, the length of the near-field light generating element 16 in thedirection perpendicular to the medium facing surface 40 (the Ydirection) will be denoted by the symbol H_(PA); the length of the thirdside 16 e 3 of the front end face 16 e will be denoted by the symbolW_(PA); and the length of the front end face 16 e in the directionperpendicular to the bottom surface 16 a (the Z direction) will bedenoted by the symbol T_(PA). H_(PA) is greater than T_(PA). Both ofW_(PA) and T_(PA) are smaller than or equal to the wavelength of lightthat is propagated through the waveguide 20. W_(PA) falls within therange of 100 to 500 nm, for example. T_(PA) falls within the range of100 to 500 nm, for example. H_(PA) falls within the range of 0.25 to 2.5μm, for example.

As shown in FIG. 2, the distance between the third side 16 e 3 and avirtual straight line passing through the points of connection 16 e 13and 16 e 23 will be denoted by the symbol T₁. The distance between theforegoing virtual straight line and the tip 16 e 4 will be denoted bythe symbol T₂. T₁ falls within the range of 75 to 400 nm, for example.T₂ falls within the range of 25 to 100 nm, for example.

As shown in FIG. 3, the magnetic pole 22 has a bottom end (bottom end ofthe first layer 22A) that is opposed to the edge part 16 d with apredetermined distance therebetween. The waveguide 20 has a bottomsurface (bottom surface of the first layer 20A) that is opposed to theedge part 16 d with a predetermined distance therebetween. At least theclad layer 19 is interposed between the edge part 16 d and the bottomend of the magnetic pole 22, and between the edge part 16 d and thebottom surface of the waveguide 20. In addition to the clad layer 19,the surrounding layer 18 may also be interposed between the edge part 16d and the bottom end of the magnetic pole 22, and between the edge part16 d and the bottom surface of the waveguide 20. The distance from theedge part 16 d to each of the bottom end of the magnetic pole 22 and thebottom surface of the waveguide 20 falls within the range of 5 to 80 nm,for example.

Now, the principle of generation of near-field light in the presentembodiment and the principle of heat-assisted magnetic recording usingthe near-field light will be described in detail. The laser lightemitted from the not-shown laser diode enters the waveguide 20. As shownin FIG. 4, the laser light 50 is propagated through the waveguide 20toward the medium facing surface 40, and reaches the vicinity of thenear-field light generating element 16. The laser light 50 is thentotally reflected at the bottom surface of the waveguide 20. Thisgenerates evanescent light permeating into the clad layer 19 and intothe surrounding layer 18 therebelow. As a result, the evanescent lightand the collective oscillations of charges on the edge part 16 d and itsvicinity in the near-field light generating element 16, i.e., surfaceplasmons, are coupled with each other to excite a system of surfaceplasmon polaritons. In this way, surface plasmons are excited on theedge part 16 d and its vicinity in the near-field light generatingelement 16.

The surface plasmons excited on the near-field light generating element16 are propagated along the edge part 16 d toward the near-field lightgenerating part 16 g. Consequently, the surface plasmons concentrate atthe near-field light generating part 16 g, and the near-field lightgenerating part 16 g generates near-field light based on the surfaceplasmons. The near-field light is projected toward the recording medium,reaches the surface of the recording medium and heats a part of themagnetic recording layer of the recording medium. This lowers thecoercivity of the part of the magnetic recording layer. In heat-assistedmagnetic recording, the part of the magnetic recording layer with thelowered coercivity is subjected to a write magnetic field produced bythe magnetic pole 22 for performing data writing.

Now, with reference to FIG. 4 and FIG. 5, a description will be given ofa method of manufacturing the heat-assisted magnetic recording headaccording to the present embodiment. The method of manufacturing theheat-assisted magnetic recording head according to the presentembodiment includes the steps of forming components of a plurality ofheat-assisted magnetic recording heads other than the substrates 1 on asubstrate that includes portions to become the substrates 1 of theplurality of heat-assisted magnetic recording heads, thereby fabricatinga substructure that includes pre-head portions arranged in a pluralityof rows, the pre-head portions being intended to become theheat-assisted magnetic recording heads later; and forming the pluralityof heat-assisted magnetic recording heads by cutting the substructure toseparate the plurality of pre-head portions from each other. In the stepof forming the plurality of heat-assisted magnetic recording heads, thesurfaces formed by cutting are polished into the medium facing surfaces40.

The method of manufacturing the heat-assisted magnetic recording headaccording to the present embodiment will now be described in more detailwith attention focused on a single heat-assisted magnetic recordinghead. In the method of manufacturing the heat-assisted magneticrecording head according to the present embodiment, the insulating layer2 is initially formed on the substrate 1. Next, the bottom shield layer3 is formed on the insulating layer 2. Next, the bottom shield gap film4 is formed on the bottom shield layer 3. Next, the MR element 5 and thenot-shown two leads connected to the MR element 5 are formed on thebottom shield gap film 4. Next, the top shield gap film 6 is formed tocover the MR element 5 and the leads. Next, the top shield layer 7 isformed on the top shield gap film 6. Next, the nonmagnetic layer 8 isformed on the top shield layer 7. Next, the return magnetic pole layer10 is formed on the nonmagnetic layer 8.

Next, the coupling layer 11 is formed on the return magnetic pole layer10. Next, the insulating layer 12 is formed to cover the coupling layer11. The insulating layer 12 is then polished by, for example, chemicalmechanical polishing (hereinafter referred to as CMP), until thecoupling layer 11 is exposed. This flattens the coupling layer 11 andthe insulating layer 12 at the top. Next, the coupling layer 13 isformed on the coupling layer 11, and the heat sink layer 14 is formed onthe insulating layer 12. Next, the insulating layer 15 is formed tocover the coupling layer 13 and the heat sink layer 14. The insulatinglayer 15 is then polished by, for example, CMP, until the coupling layer13 and the heat sink layer 14 are exposed. This flattens the couplinglayer 13, the heat sink layer 14, and the insulating layer 15 at thetop.

Next, the coupling layer 17 is formed on the coupling layer 13, and thenear-field light generating element 16 and the surrounding layer 18 areformed on top of the heat sink layer 14 and the insulating layer 15. Thestep of forming the near-field light generating element 16 and thesurrounding layer 18 will be described in detail later.

Next, the clad layer 19 is formed over the coupling layer 17 and thesurrounding layer 18. The clad layer 19 has two openings that arelocated above the coupling layer 17. The two openings are intended forpassing the coupling portions 29A and 29B therethrough. Next, therespective first layers of the coupling portions 29A and 29B are formedto be coupled to the coupling layer 17 through the two openings. Thefirst layer 20A of the waveguide 20, the first layer 22A of the magneticpole 22, and the clad layer 21 are formed on the clad layer 19.

Next, the second layer 20B of the waveguide 20 is formed on the firstlayer 20A, and the second layer 22B of the magnetic pole 22 is formed onthe first layer 22A. The respective second layers of the couplingportions 29A and 29B are formed on the respective first layers of thecoupling portions 29A and 29B. Next, the clad layer 23 is formed tocover the second layer 20B, the second layer 22B, and the respectivesecond layers of the coupling portions 29A and 29B. Next, the clad layer23 is polished by, for example, CMP, until the second layer 22B and therespective second layers of the coupling portions 29A and 29B areexposed.

Next, the third layer 22C of the magnetic pole 22 is formed on thesecond layer 22B, and the coupling layer 24 is formed to be coupled tothe coupling portions 29A and 29B. Next, the insulating layer 25 isformed to cover the third layer 22C and the coupling layer 24. Theinsulating layer 25 is then polished by, for example CMP, until thethird layer 22C and the coupling layer 24 are exposed.

Next, the insulating layer 28 is formed on the insulating layer 25.Next, the first coil elements 30A are formed on the insulating layer 28.The coupling layer 26 is formed on the third layer 22C of the magneticpole 22, and the coupling layer 27 is formed on the coupling layer 24.Next, the insulating layer 31 is formed to cover the first coil elements30A and the coupling layers 26 and 27. The insulating layer 31 is thenpolished by, for example, CMP, until the first coil elements 30A and thecoupling layers 26 and 27 are exposed.

Next, the insulating layer 32 is formed to cover the first coil elements30A. The insulating layer 32 has a plurality of openings for passing theconnecting portions 36 and 37 therethrough. Next, the connectingportions 36 and 37 are formed to be connected to the first coil elements30A through the plurality of openings. Next, the yoke layer 33 is formedover the coupling layers 26 and 27 and the insulating layer 32. Next,the insulating layer 34 is formed to cover the yoke layer 33 and theconnecting portions 36 and 37. The insulating layer 34 is then polishedby, for example, CMP, until the connecting portions 36 and 37 areexposed.

Next, the second coil elements 30B and the lead layer 30C are formed onthe connecting portions 36 and 37 and the insulating layer 34. Next, theprotection layer 35 is formed to cover the second coil elements 30B andthe lead layer 30C. Wiring, terminals, and other components are thenformed on the top surface of the protection layer 35.

When the substructure is completed thus, the substructure is cut toseparate the plurality of pre-head portions from each other, followed bythe polishing of the medium facing surface 40 and the fabrication offlying rails etc. This completes the heat-assisted magnetic recordinghead.

The step of forming the near-field light generating element 16 and thesurrounding layer 18 will now be described in detail with reference toFIG. 8 to FIG. 21. The step of forming the near-field light generatingelement 16 and the surrounding layer 18 includes forming the near-fieldlight generating element 16. The following description includes thedescription of the method of manufacturing the near-field lightgenerating element 16 according to the present embodiment. FIG. 8 toFIG. 21 each show a cross section of a stack of layers in the process offorming the near-field light generating element 16 and the surroundinglayer 18, the cross section being taken at the position where the mediumfacing surface 40 is to be formed.

FIG. 8 shows a step after the formation of the heat sink layer 14 andthe insulating layer 15. In this step, a metal layer 16P is initiallyformed over the heat sink layer 14 and the insulating layer 15 bysputtering, for example. The metal layer 16P is to be etched later tobecome the near-field light generating element 16. The metal layer 16Phas a thickness in the range of 100 to 500 nm, for example. Next, apolishing stopper layer 51 is formed on the metal layer 16P bysputtering, for example. The polishing stopper layer 51 is intended foruse in a polishing step to be performed later. The polishing stopperlayer 51 has a thickness in the range of 20 to 60 nm, for example. Thepolishing stopper layer 51 includes a layer of Ta or Ru, for example.The polishing stopper layer 51 may include a first layer of Ta or Ru,for example, and a second layer of NiCr, for example, which is formed onthe first layer.

FIG. 9 shows the next step. In this step, a photoresist mask 52 isinitially formed on the polishing stopper layer 51. Next, the polishingstopper layer 51 is etched by, for example, ion beam etching(hereinafter referred to as IBE) or reactive ion etching (hereinafterreferred to as RIE), by using the photoresist mask 52 as the etchingmask. The polishing stopper layer 51 thus etched covers an area of themetal layer 16P where the second inclined surface 16 c is to be formedlater.

FIG. 10 and FIG. 11 show the next step. In this step, the polishingstopper layer 51 and the metal layer 16P are etched so that the metallayer 16P is provided with the first inclined surface 16 b. This stepwill be referred to as a first etching step. In the first etching step,as shown in FIG. 10, the polishing stopper layer 51 and the metal layer16P are initially etched by, for example, IBE, by using the photoresistmask 52 as the etching mask. This etching is performed so that thedirection of travel of the ion beam forms an angle in the range of 30°to 60° with respect to the direction perpendicular to the bottom surfaceof the metal layer 16P. This provides the metal layer 16P with a firstinitial inclined surface 16Pb that is to become the first inclinedsurface 16 b later.

In the first etching step, as shown in FIG. 11, the first initialinclined surface 16Pb is then etched by, for example, IBE, by using thephotoresist mask 52 as the etching mask. This etching is performed sothat the direction of travel of the ion beam forms an angle in the rangeof 0° to 30° with respect to the direction perpendicular to the bottomsurface of the metal layer 16P. This provides the first initial inclinedsurface 16Pb with the lower part 16 b 1 and the upper part 16 b 2 of thefirst inclined surface 16 b, and thereby makes the first initialinclined surface 16Pb into the first inclined surface 16 b. It should benoted that sputter etching or RIE may be employed instead of IBE whenetching the first initial inclined surface 16Pb. Next, the photoresistmask 52 is removed.

FIG. 12 shows the next step. In this step, a coating layer 18A is formedto cover the polishing stopper layer 51 and the metal layer 16P providedwith the first inclined surface 16 b. The coating layer 18A is formedalso over the heat sink layer 14 and the insulating layer 15. Thecoating layer 18A is formed to have such a thickness that the topsurface of the portion formed over the heat sink layer 14 and theinsulating layer 15 lies at a level higher than the top surface of thepolishing stopper layer 51. The thickness of the coating layer 18A fallswithin the range of 0.2 to 0.8 μm, for example. The coating layer 18A ismade of a non-metallic inorganic material that has an etching rate lowerthan that of the metal layer 16P in a second etching step to beperformed later. While the material of the coating layer 18A may beeither an inorganic dielectric material or an inorganic semiconductormaterial, the former is preferred. The coating layer 18A may be made ofone selected from the group consisting of Al₂O₃, SiO₂, Ta₂O₅, SiC, andTiN.

FIG. 13 shows the next step. In this step, the coating layer 18A ispolished by, for example, CMP, until the polishing stopper layer 51 isexposed. This step will be referred to as a polishing step.

FIG. 14 shows the next step. In this step, a second polishing stopperlayer 53 is formed over the polishing stopper layer 51 and the coatinglayer 18A. The second polishing stopper layer 53 is intended for use ina second polishing step to be performed later. The thickness andmaterial of the second polishing stopper layer 53 are the same as thoseof the polishing stopper layer 51.

FIG. 15 shows the next step. In this step, a photoresist mask 54 isinitially formed on the second polishing stopper layer 53. Next, thesecond polishing stopper layer 53 is etched by, for example, IBE or RIE,by using the photoresist mask 54 as the etching mask. After the etching,the second polishing stopper layer 53 no longer lies on the polishingstopper layer 51 but lies on the coating layer 18A.

FIG. 16 and FIG. 17 show the next step. In this step, the polishingstopper layer 51 and the metal layer 16P are etched by using the coatinglayer 18A polished in the polishing step as the etching mask so that themetal layer 16P is provided with the second inclined surface 16 c andthe edge part 16 d and thereby becomes the near-field light generatingelement 16. This step will be referred to as a second etching step. Inthe second etching step, as shown in FIG. 16, the polishing stopperlayer 51 and the metal layer 16P are initially etched by, for example,IBE, by using the coating layer 18A polished in the polishing step asthe etching mask. This etching is performed so that the direction oftravel of the ion beam forms an angle in the range of 30° to 60° withrespect to the direction perpendicular to the bottom surface of themetal layer 16P. This provides the metal layer 16P with a second initialinclined surface 16Pc that is to become the second inclined surface 16 clater.

In the second etching step, as shown in FIG. 17, the second initialinclined surface 16Pc is then etched by, for example, sputter etching,by using the coating layer 18A polished in the polishing step as theetching mask. This provides the second initial inclined surface 16Pcwith the lower part 16 c 1 and the upper part 16 c 2 of the secondinclined surface 16 c, and thereby makes the second initial inclinedsurface 16Pc into the second inclined surface 16 c. This also providesthe metal layer 16P with the edge part 16 d, and thereby makes the metallayer 16P into the near-field light generating element 16. It should benoted that IBE or RIE may be employed instead of sputter etching whenetching the second initial inclined surface 16Pc. Next, the photoresistmask 54 is removed.

In the second etching step, as shown in FIG. 17, the coating layer 18Ais slightly etched, so that the coating layer 18A is provided with aninclined surface 18A1 continuous with the upper part 16 c 2 of thesecond inclined surface 16 c. In the second etching step, the coatinglayer 18A has an etching rate lower than that of the metal layer 16P.Thus, in the second etching step, the inclined surface 18A1 is formed toconstitute a single flat surface with the upper part 16 c 2 of thesecond inclined surface 16 c without being rounded. Consequently, theedge part 16 d is formed into a sharply pointed shape without beingrounded.

FIG. 18 shows the next step. In this step, a second coating layer 18B isformed to cover the near-field light generating element 16, the coatinglayer 18A, and the second polishing stopper layer 53. The second coatinglayer 18B is formed also over the heat sink layer 14 and the insulatinglayer 15. The second coating layer 18B is formed to have such athickness that the top surface of the portion formed over the heat sinklayer 14 and the insulating layer 15 lies at a level higher than the topsurface of the second polishing stopper layer 53. The thickness of thesecond coating layer 18B falls within the range of 0.2 to 0.8 μm, forexample. While the second coating layer 18B can be made of any materialother than conductive materials, it is preferred that the second coatinglayer 18B be made of the same material as the coating layer 18A.

FIG. 19 shows the next step. In this step, the second coating layer 18Bis polished by, for example, CMP, until the second polishing stopperlayer 53 is exposed. This step will be referred to as a second polishingstep.

FIG. 20 shows the next step. In this step, IBE or RIE, for example, isperformed to remove the second polishing stopper layer 53 and slightlyetch the second coating layer 18B so that the coating layer 18A and thesecond coating layer 18B are flattened at the top. The coating layer 18Aand the second coating layer 18B remaining after this step constitutethe surrounding layer 18.

The near-field light generating element 16 and the surrounding layer 18are formed through the series of steps shown in FIG. 8 to FIG. 20. FIG.21 shows a step after the formation of the near-field light generatingelement 16 and the surrounding layer 18. In this step, the clad layer 19is initially formed on the surrounding layer 18. Next, the clad layer21, the first layer 22A of the magnetic pole 22, and the first layer 20A(not shown) of the waveguide 20 are formed on the clad layer 19.

As has been described, the heat-assisted magnetic recording headaccording to the present embodiment includes the near-field lightgenerating element 16, the waveguide 20, and the magnetic pole 22. Theouter surface of the near-field light generating element 16 includes thebottom surface 16 a, the first and second inclined surfaces 16 b and 16c, and the edge part 16 d that connects the first and second inclinedsurfaces 16 b and 16 c to each other. The outer surface of thenear-field light generating element 16 further includes the front endface 16 e located in the medium facing surface, and the rear end face 16f opposite to the front end face 16 e. The front end face 16 e has thefirst side 16 e 1 lying at an end of the first inclined surface 16 b,the second side 16 e 2 lying at an end of the second inclined surface 16c, the third side 16 e 3 lying at an end of the bottom surface 16 a, andthe tip 16 e 4 that is formed by contact of the first side 16 e 1 andthe second side 16 e 2 with each other and forms the near-field lightgenerating part 16 g.

In the present embodiment, the bottom surface of the waveguide 20 isopposed to the edge part 16 d of the near-field light generating element16 with a predetermined distance therebetween. In the presentembodiment, evanescent light occurs from the bottom surface of thewaveguide 20 based on the light propagated through the waveguide 20.Based on the evanescent light, surface plasmons are then excited on theedge part 16 d and its vicinity in the near-field light generatingelement 16. The surface plasmons are propagated along the edge part 16 dto the near-field light generating part 16 g, and near-field lightoccurs from the near-field light generating part 16 g based on thesurface plasmons. According to the present embodiment, it is possible toincrease the efficiency of transformation of the light propagatedthrough the waveguide 20 into the near-field light, as compared with theconventional case where a plasmon antenna is directly irradiated withlaser light to produce near-field light.

According to the present embodiment, it is possible suppress atemperature rise of the near-field light generating element 16 becausethe near-field light generating element 16 is not directly irradiatedwith the laser light propagated through the waveguide 20. In the presentembodiment, the length H_(PA) of the near-field light generating element16 in the direction perpendicular to the medium facing surface 40 isgreater than the length T_(PA) of the front end face 16 e in thedirection perpendicular to the bottom surface 16 a of the near-fieldlight generating element 16. Thus, the near-field light generatingelement 16 of the present embodiment is greater in volume than aconventional plasmon antenna in which the length in the directionperpendicular to the medium facing surface 40 is smaller than the lengthin the direction perpendicular to the top surface 1 a of the substrate1. This also contributes to suppression of a temperature rise of thenear-field light generating element 16. Consequently, according to thepresent embodiment, it is possible to prevent the near-field lightgenerating element 16 from protruding from the medium facing surface 40.

In the present embodiment, the first inclined surface 16 b includes thelower part 16 b 1 and the upper part 16 b 2 that are continuous witheach other. The second inclined surface 16 c includes the lower part 16c 1 and the upper part 16 c 2 that are continuous with each other. Thefirst side 16 e 1 includes the lower part 16 e 11 and the upper part 16e 12 that are continuous with each other. The second side 16 e 2includes the lower part 16 e 21 and the upper part 16 e 22 that arecontinuous with each other. The angle θ2 that is formed between theupper part 16 b 2 of the first inclined surface 16 b and the upper part16 c 2 of the second inclined surface 16 c, and that is formed betweenthe upper part 16 e 12 of the first side 16 e 1 and the upper part 16 e22 of the second side 16 e 2, is smaller than the angle θ1 that isformed between the lower part 16 b 1 of the first inclined surface 16 band the lower part 16 c 1 of the second inclined surface 16 c, and thatis formed between the lower part 16 e 11 of the first side 16 e 1 andthe lower part 16 e 21 of the second side 16 e 2. This makes it possibleto form the tip 16 e 4 and its vicinity constituting the near-fieldlight generating part 16 g into a fine and sharply pointed shape in thefront end face 16 e of the near-field light generating element 16.

According to the present embodiment, the near-field light generatingelement 16 having the foregoing shape allows a lot of surface plasmonsto concentrate at the near-field light generating part 16 g having apointed shape. Consequently, according to the present embodiment, it ispossible to generate near-field light that has a small spot diameter andsufficient intensity.

In the method of manufacturing the near-field light generating element16 according to the present embodiment, the polishing stopper layer 51and the metal layer 16P are etched in the second etching step by usingthe coating layer 18A polished in the polishing step as the etchingmask. This provides the metal layer 16P with the second inclined surface16 c and the edge part 16 d, and thereby makes the metal layer 16P intothe near-field light generating element 16. The coating layer 18A ismade of a non-metallic inorganic material that has an etching rate lowerthan that of the metal layer 16P in the second etching step. Accordingto the present embodiment, as has been described with reference to FIG.17, it is therefore possible to prevent the edge part 16 d from beingrounded in the second etching step. The edge part 16 d can thus beformed into a sharply pointed shape. Consequently, according to thepresent embodiment, it is possible to manufacture the near-field lightgenerating element 16 that has the front end face 16 e with the top end,i.e., tip 16 e 4, having a sharply pointed shape. The tip 16 e 4 formsthe near-field light generating part 16 g. According to the presentembodiment, it is possible to concentrate a lot of surface plasmons atthe tip 16 e 4 (the near-field light generating part 16 g) of sharplypointed shape. Consequently, the present embodiment makes it possible togenerate near-field light having a small spot diameter and sufficientintensity.

In the present embodiment, the step of forming the near-field lightgenerating element 16 includes the step of forming the second polishingstopper layer 53 on the coating layer 18A between the polishing step andthe second etching step. The second polishing stopper layer 53 isintended for use in the second polishing step to be performed later. Themethod of manufacturing the heat-assisted magnetic recording headaccording to the present embodiment includes: the step of forming thesecond coating layer 18B to cover the near-field light generatingelement 16, the coating layer 18A and the second polishing stopper layer53 after the second etching step; the second polishing step of polishingthe second coating layer 18B until the second polishing stopper layer 53is exposed; and the step of removing the second polishing stopper layer53 after the second polishing step. According to the present embodiment,it is thus possible to define the level of the top surface of the secondcoating layer 18B while preventing the edge part 16 d of the near-fieldlight generating element 16 from being polished. Consequently, accordingto the present embodiment, it is possible to precisely define thedistance between the edge part 16 d and the magnetic pole 22 and thedistance between the edge part 16 d and the waveguide 20.

Second Embodiment

A near-field light generating element and a method of manufacturing thesame, and a heat-assisted magnetic recording head according to a secondembodiment of the invention will now be described with reference to FIG.22 to FIG. 35. FIG. 22 to FIG. 35 show the step of forming thenear-field light generating element 16 and the surrounding layer 18 ofthe present embodiment. The step of forming the near-field lightgenerating element 16 and the surrounding layer 18 includes forming thenear-field light generating element 16. The following descriptionincludes the description of the method of manufacturing the near-fieldlight generating element 16 according to the present embodiment. FIG. 22to FIG. 35 each show a cross section of a stack of layers in the processof forming the near-field light generating element 16 and thesurrounding layer 18, the cross section being taken at the positionwhere the medium facing surface 40 is to be formed.

FIG. 22 shows a step after the formation of the heat sink layer 14 andthe insulating layer 15. In this step, an accommodating layer 61 isinitially formed over the heat sink layer 14 and the insulating layer15. The accommodating layer 61 is made of a material that has an etchingrate lower than that of the metal layer 16P in first and second etchingsteps to be performed later. The accommodating layer 61 has anaccommodating part 61 a in which the metal layer 16P is to beaccommodated later. Like the coating layer 18A of the first embodiment,the accommodating layer 61 may be made of a non-metallic inorganicmaterial. The accommodating layer 61 has a thickness greater than thelength T_(PA) of the front end face 16 e of the near-field lightgenerating element 16. The accommodating part 61 a penetrates throughthe accommodating layer 61. The cross section of the accommodating part61 a parallel to the top surfaces of the heat sink layer 14 and theinsulating layer 15 increases in size with increasing distance from thetop surfaces of the heat sink layer 14 and the insulating layer 15.

The accommodating layer 61 is formed in the following way, for example.First, an initial accommodating layer is formed over the heat sink layer14 and the insulating layer 15. The initial accommodating layer is to beetched later to become the accommodating layer 61. Next, a photoresistmask 62 having an opening 62 a is formed on the initial accommodatinglayer. Next, the initial accommodating layer is taper-etched by, forexample, RIE, by using the photoresist mask 62 as the etching mask. Thisprovides the initial accommodating layer with the accommodating part 61a, and thereby makes the initial accommodating layer into theaccommodating layer 61.

FIG. 23 shows the next step. In this step, the metal layer 16P isinitially formed by, for example, sputtering, so as to be accommodatedin the accommodating part 61 a. Next, the accommodating layer 61 and themetal layer 16P are flattened at the top by CMP, for example. At thispoint in time, the metal layer 16P has a thickness in the range of 100to 500 nm, for example. Next, a polishing stopper layer 63 is formedover the accommodating layer 61 and the metal layer 16P by sputtering,for example. The polishing stopper layer 63 is intended for use in apolishing step to be performed later. The thickness and material of thepolishing stopper layer 63 are the same as those of the polishingstopper layer 51 of the first embodiment.

FIG. 24 shows the next step. In this step, a photoresist mask 64 isinitially formed on the polishing stopper layer 63. Next, the polishingstopper layer 63 is etched by, for example, IBE, by using thephotoresist mask 64 as the etching mask. The polishing stopper layer 63thus etched covers an area of the metal layer 16P where the secondinclined surface 16 c is to be formed later.

FIG. 25 and FIG. 26 show the next step. In this step, the polishingstopper layer 63 and the metal layer 16P are etched so that the metallayer 16P is provided with the first inclined surface 16 b. This stepwill be referred to as a first etching step. In the first etching step,as shown in FIG. 25, the polishing stopper layer 63 and the metal layer16P are initially etched by, for example, IBE, by using the photoresistmask 64 as the etching mask. This etching is performed so that thedirection of travel of the ion beam forms an angle in the range of 30°to 60° with respect to the direction perpendicular to the bottom surfaceof the metal layer 16P. This provides the metal layer 16P with a firstinitial inclined surface 16Pb that is to become the first inclinedsurface 16 b later.

In the first etching step, as shown in FIG. 26, the first initialinclined surface 16Pb is then etched by, for example, IBE, by using thephotoresist mask 64 as the etching mask. This etching is performed sothat the direction of travel of the ion beam forms an angle in the rangeof 0° to 30° with respect to the direction perpendicular to the bottomsurface of the metal layer 16P. This provides the first initial inclinedsurface 16Pb with the lower part 16 b 1 and the upper part 16 b 2 of thefirst inclined surface 16 b, and thereby makes the first initialinclined surface 16Pb into the first inclined surface 16 b. It should benoted that sputter etching or RIE may be employed instead of IBE whenetching the first initial inclined surface 16Pb. Next, the photoresistmask 64 is removed.

FIG. 27 shows the next step. In this step, the coating layer 18A isformed to cover the polishing stopper layer 63 and the metal layer 16Pprovided with the first inclined surface 16 b. The coating layer 18A isformed also over the heat sink layer 14 and the insulating layer 15. Thecoating layer 18A is formed to have such a thickness that the topsurface of the portion formed over the heat sink layer 14 and theinsulating layer 15 lies at a level higher than the top surface of thesecond polishing stopper layer 63. The thickness of the coating layer18A falls within the range of 0.2 to 0.8 μm, for example. The coatinglayer 18A is made of a non-metallic inorganic material that has anetching rate lower than that of the metal layer 16P in a second etchingstep to be performed later. The material of the coating layer 18A is thesame as in the first embodiment.

FIG. 28 shows the next step. In this step, the coating layer 18A ispolished by, for example, CMP, until the polishing stopper layer 63 isexposed. This step will be referred to as a polishing step.

FIG. 29 shows the next step. In this step, a photoresist mask 65 isformed on top of the polishing stopper layer 63 and the coating layer18A. The photoresist mask 65 has an opening that is located above a partof the metal layer 16P that is to be etched in the second etching stepto be performed later.

FIG. 30 and FIG. 31 show the next step. In this step, the polishingstopper layer 63 and the metal layer 16P are etched by using the coatinglayer 18A polished in the polishing step as the etching mask so that themetal layer 16P is provided with the second inclined surface 16 c andthe edge part 16 d and thereby becomes the near-field light generatingelement 16. This step will be referred to as a second etching step. Inthe second etching step, as shown in FIG. 30, the polishing stopperlayer 63 and the metal layer 16P are initially etched by, for example,IBE, by using the coating layer 18A polished in the polishing step asthe etching mask. This etching is performed so that the direction oftravel of the ion beam forms an angle in the range of 30° to 60° withrespect to the direction perpendicular to the bottom surface of themetal layer 16P. This provides the metal layer 16P with a second initialinclined surface 16Pc that is to become the second inclined surface 16 clater.

In the second etching step, as shown in FIG. 31, the second initialinclined surface 16Pc is then etched by, for example, sputter etching,by using the coating layer 18A polished in the polishing step as theetching mask. This provides the second initial inclined surface 16Pcwith the lower part 16 c 1 and the upper part 16 c 2 of the secondinclined surface 16 c, and thereby makes the second initial inclinedsurface 16Pc into the second inclined surface 16 c. This also providesthe metal layer 16P with the edge part 16 d, and thereby makes the metallayer 16P into the near-field light generating element 16. It should benoted that IBE or RIE may be employed instead of sputter etching whenetching the second initial inclined surface 16Pc. Next, the photoresistmask 65 is removed.

In the second etching step, as shown in FIG. 31, the coating layer 18Ais slightly etched, so that the coating layer 18A is provided with aninclined surface 18A1 continuous with the upper part 16 c 2 of thesecond inclined surface 16 c. In the second etching step, the coatinglayer 18A has an etching rate lower than that of the metal layer 16P.Thus, in the second etching step, the inclined surface 18A1 is formed toconstitute a single flat surface with the upper part 16 c 2 of thesecond inclined surface 16 c without being rounded. Consequently, theedge part 16 d is formed into a sharply pointed shape without beingrounded. After the second etching step, the polishing stopper layer 63remains on the accommodating layer 61. In the second etching step, themetal layer 16P is preferably etched so that the edge part 16 d lies ata level lower than the bottom surface of the polishing stopper layer 63.

FIG. 32 shows the next step. In this step, the second coating layer 18Bis formed to cover the accommodating layer 61, the polishing stopperlayer 63, the near-field light generating element 16, and the coatinglayer 18A. The second coating layer 18B is formed also over the heatsink layer 14 and the insulating layer 15. The second coating layer 18Bis formed to have such a thickness that the top surface of the portionformed over the heat sink layer 14 and the insulating layer 15 lies at alevel higher than the top surface of the polishing stopper layer 63. Thethickness and material of the second coating layer 18B are the same asin the first embodiment.

FIG. 33 shows the next step. In this step, the second coating layer 18Bis polished by, for example, CMP, until the polishing stopper layer 63is exposed. This step will be referred to as a second polishing step.

FIG. 34 shows the next step. In this step, IBE or RIE, for example, isperformed to remove the polishing stopper layer 63 and slightly etch thesecond coating layer 18B so that the coating layer 18A and the secondcoating layer 18B are flattened at the top. The coating layer 18A andthe second coating layer 18B remaining after this step constitute thesurrounding layer 18.

The near-field light generating element 16 and the surrounding layer 18are formed through the series of steps shown in FIG. 22 to FIG. 34. FIG.35 shows a step after the formation of the near-field light generatingelement 16 and the surrounding layer 18. In this step, the clad layer 19is initially formed on the surrounding layer 18. Next, the clad layer21, the first layer 22A of the magnetic pole 22, and the first layer 20A(not shown) of the waveguide 20 are formed on the clad layer 19.

In the present embodiment, the second polishing stopper layer of thefirst embodiment is not formed. Instead, in the present embodiment, thepolishing stopper layer 63 remains on the accommodating layer 61 afterthe second etching step. The method of manufacturing the heat-assistedmagnetic recording head according to the present embodiment includes:the step of forming the second coating layer 18B to cover theaccommodating layer 61, the polishing stopper layer 63, the near-fieldlight generating element 16 and the coating layer 18A after the secondetching step; the second polishing step of polishing the second coatinglayer 18B until the polishing stopper layer 63 is exposed; and the stepof removing the polishing stopper layer 63 after the second polishingstep. According to the present embodiment, it is thus possible to definethe level of the top surface of the second coating layer 18B whilepreventing the edge part 16 d of the near-field light generating element16 from being polished. Consequently, according to the presentembodiment, it is possible to precisely define the distance between theedge part 16 d and the magnetic pole 22 and the distance between theedge part 16 d and the waveguide 20.

The remainder of configuration, function and effects of the presentembodiment are similar to those of the first embodiment.

The present invention is not limited to the foregoing embodiments, andvarious modifications may be made thereto. For example, in the presentinvention, the clad layer 19 alone may be interposed between the edgepart 16 d of the near-field light generating element 16 and the bottomsurface of the waveguide 20, and between the edge part 16 d and thebottom end of the magnetic pole 22, without the intervention of thesurrounding layer 18.

It is apparent that the present invention can be carried out in variousforms and modifications in the light of the foregoing descriptions.Accordingly, within the scope of the following claims and equivalentsthereof, the present invention can be carried out in forms other thanthe foregoing most preferable embodiments.

1. A near-field light generating element for use in a heat-assistedmagnetic recording head, the heat-assisted magnetic recording headcomprising: a medium facing surface that faces a recording medium; amagnetic pole that has an end face located in the medium facing surfaceand produces a write magnetic field for writing data on the recordingmedium; a waveguide that propagates light; the near-field lightgenerating element that has a near-field light generating part locatedin the medium facing surface, a surface plasmon being excited based onthe light propagated through the waveguide, the surface plasmon beingpropagated to the near-field light generating part, the near-field lightgenerating part generating near-field light based on the surfaceplasmon; and a substrate having a top surface, the near-field lightgenerating element, the magnetic pole, and the waveguide being disposedabove the top surface of the substrate, wherein: the near-field lightgenerating element has an outer surface; the outer surface includes: abottom surface that lies at an end closer to the top surface of thesubstrate; first and second inclined surfaces that are each connected tothe bottom surface, the first and second inclined surfaces decreasing indistance from each other with increasing distance from the bottomsurface; an edge part that connects the first and second inclinedsurfaces to each other; and a front end face that is located in themedium facing surface and connects the bottom surface and the first andsecond inclined surfaces to each other; the front end face has: a firstside that lies at an end of the first inclined surface; a second sidethat lies at an end of the second inclined surface; a third side thatlies at an end of the bottom surface; and a tip that is formed bycontact of the first and second sides with each other and forms thenear-field light generating part; each of the first side and the secondside includes a lower part and an upper part that are continuous witheach other; and an angle formed between the upper part of the first sideand the upper part of the second side is smaller than that formedbetween the lower part of the first side and the lower part of thesecond side.
 2. The near-field light generating element according toclaim 1, wherein: each of the first inclined surface and the secondinclined surface includes a lower part and an upper part that arecontinuous with each other; an angle formed between the upper part ofthe first inclined surface and the upper part of the second inclinedsurface is smaller than that formed between the lower part of the firstinclined and the lower part of the second inclined surface; the lowerpart of the first side lies at an end of the lower part of the firstinclined surface; the upper part of the first side lies at an end of theupper part of the first inclined surface; the lower part of the secondside lies at an end of the lower part of the second inclined surface;and the upper part of the second side lies at an end of the upper partof the second inclined surface.
 3. A method of manufacturing thenear-field light generating element according to claim 2, comprising: astep of forming a metal layer that is to be etched later to become thenear-field light generating element; a first etching step of etching themetal layer so that the metal layer is provided with the first inclinedsurface; and a second etching step of etching the metal layer so thatthe metal layer is provided with the second inclined surface and theedge part and thereby becomes the near-field light generating element,wherein: the first etching step includes: a step of providing the metallayer with a first initial inclined surface that is to become the firstinclined surface later; and a step of etching the first initial inclinedsurface so that the first initial inclined surface is provided with thelower part and the upper part of the first inclined surface and therebybecomes the first inclined surface; and the second etching stepincludes: a step of providing the metal layer with a second initialinclined surface that is to become the second inclined surface later;and a step of etching the second initial inclined surface so that thesecond initial inclined surface is provided with the lower part and theupper part of the second inclined surface and thereby becomes the secondinclined surface.
 4. A method of manufacturing the near-field lightgenerating element according to claim 2, comprising: a step of forming ametal layer that is to be etched later to become the near-field lightgenerating element; a step of forming a polishing stopper layer on themetal layer, the polishing stopper layer being intended for use in apolishing step to be performed later; a first etching step of etchingthe polishing stopper layer and the metal layer so that the metal layeris provided with the first inclined surface; a step of forming a coatinglayer to cover the polishing stopper layer and the metal layer providedwith the first inclined surface, the coating layer being made of anon-metallic inorganic material that has an etching rate lower than thatof the metal layer in a second etching step to be performed later; thepolishing step of polishing the coating layer until the polishingstopper layer is exposed; and the second etching step of etching thepolishing stopper layer and the metal layer by using the coating layerpolished in the polishing step as an etching mask so that the metallayer is provided with the second inclined surface and the edge part andthereby becomes the near-field light generating element, wherein: thefirst etching step includes: a step of providing the metal layer with afirst initial inclined surface that is to become the first inclinedsurface later; and a step of etching the first initial inclined surfaceso that the first initial inclined surface is provided with the lowerpart and the upper part of the first inclined surface and therebybecomes the first inclined surface; and the second etching stepincludes: a step of providing the metal layer with a second initialinclined surface that is to become the second inclined surface later;and a step of etching the second initial inclined surface so that thesecond initial inclined surface is provided with the lower part and theupper part of the second inclined surface and thereby becomes the secondinclined surface.
 5. The method of manufacturing the near-field lightgenerating element according to claim 4, wherein the coating layer ismade of one selected from the group consisting of Al₂O₃, SiO₂, Ta₂O₅,SiC, and TiN.
 6. A heat-assisted magnetic recording head comprising: amedium facing surface that faces a recording medium; a magnetic polethat has an end face located in the medium facing surface and produces awrite magnetic field for writing data on the recording medium; awaveguide that propagates light; a near-field light generating elementthat has a near-field light generating part located in the medium facingsurface, a surface plasmon being excited based on the light propagatedthrough the waveguide, the surface plasmon being propagated to thenear-field light generating part, the near-field light generating partgenerating near-field light based on the surface plasmon; and asubstrate having a top surface, wherein: the near-field light generatingelement, the magnetic pole, and the waveguide are disposed above the topsurface of the substrate; the near-field light generating element has anouter surface; the outer surface includes: a bottom surface that lies atan end closer to the top surface of the substrate; first and secondinclined surfaces that are each connected to the bottom surface, thefirst and second inclined surfaces decreasing in distance from eachother with increasing distance from the bottom surface; an edge partthat connects the first and second inclined surfaces to each other; anda front end face that is located in the medium facing surface andconnects the bottom surface and the first and second inclined surfacesto each other; the front end face has: a first side that lies at an endof the first inclined surface; a second side that lies at an end of thesecond inclined surface; a third side that lies at an end of the bottomsurface; and a tip that is formed by contact of the first and secondsides with each other and forms the near-field light generating part;each of the first side and the second side includes a lower part and anupper part that are continuous with each other; and an angle formedbetween the upper part of the first side and the upper part of thesecond side is smaller than that formed between the lower part of thefirst side and the lower part of the second side.
 7. The heat-assistedmagnetic recording head according to claim 6, wherein: each of the firstinclined surface and the second inclined surface includes a lower partand an upper part that are continuous with each other; an angle formedbetween the upper part of the first inclined surface and the upper partof the second inclined surface is smaller than that formed between thelower part of the first inclined and the lower part of the secondinclined surface; the lower part of the first side lies at an end of thelower part of the first inclined surface; the upper part of the firstside lies at an end of the upper part of the first inclined surface; thelower part of the second side lies at an end of the lower part of thesecond inclined surface; and the upper part of the second side lies atan end of the upper part of the second inclined surface.
 8. Theheat-assisted magnetic recording head according to claim 6, wherein themagnetic pole has a bottom end that is opposed to the edge part of thenear-field light generating element.
 9. The heat-assisted magneticrecording head according to claim 6, wherein the waveguide has a bottomsurface that is opposed to the edge part of the near-field lightgenerating element.